TI, whose real name is Clifford Harris Jr, was on supervised release after serving 10 months in prison for federal weapons charges when he was arrested on September 1.

Earlier this month a Georgia judge sentenced him to another 11 months in prison for breaking his federal parole with the latest arrest.

As a condition of his release earlier this year, TI was ordered not to commit another federal, state or local crime while on supervised release, or to illegally possess a controlled substance. He was also told to take at least three drug tests after his release and to participate in a drug and alcohol treatment program.

The deputy district attorney in LA said the forthcoming prison term and the small amount of drugs found were the reasons reasons drug charges were not being pursued.

"The Los Angeles District Attorney's Office's decision to reject TI's case was the right thing to do under the circumstances," TI's lawyer wrote in an email.

He commended the office for "exercising its discretion to reject prosecution in light of the legal and factual issues involved".

The Grammy Award-winning rapper is expected to begin his prison term on November 1.